This invention relates to the cooling or heating of fluids and/or the condensation of vapours and gases. Hitherto, the supply of either hot or cold liquids or beverages usually required the installation of storage type refrigerated cabinets which by necessity of their design consume power not only to condition (i.e., cool or heat) a product, but also to maintain the desired temperature in the storage container or cabinet itself. Additionally, the majority of refrigeration systems employ the use of electric motor driven compressor condensing units incorporating high pressure refrigerants which are expensive to build, contain many moving parts, suffer from vibration, wear and tear, and are costly to repair.
Conventional heat pumps which employ mechanical refrigeration systems are very cost efficient particularly in the heating mode, but because they use mechanical pumps are relatively costly and space consuming when applied to small capacity applications.